I am sorry to hear about this incident. I do not know if I can offer you much advice on this since I am not an expert on the law but I will tell you what I do know. In addition, I will ask my husband who has his degree in Criminal Justice and Pre-law and get back to you with a better answer.

If Duncan was outside and he was off a leash and bit your neighbor, then you would be in trouble. I think that since your neighbor's injuries aren't that bad, this will probably go away. I would go over and visit the guy and appologize for Duncan's behavior. Offer to pay the bill if there is one and advise him to stay away from your house.

I know I haven't helped much, but will try and get an answer to you ASAP. Perhaps someone else here has more expertise on this.